Wheelchair cushion modification and its effect on pressure.

Prevention of pressure sores is a major objective in the rehabilitation of individuals with paraplegia and quadriplegia. Wheelchair cushions made of polyurethane foam are frequently prescribed to relieve pressure and reduce the risk of ulceration for persons seated in wheelchairs. Because no cushion uniformly distributes pressure for all diagnostic groups, it may become necessary to modify a commercial cushion to provide protection against the effects of pressure. In this study, foam wheelchair cushions were geometrically modified by removing wedges from their wheelchair contacting side to reduce ischial pressure. Ischial pressures of 30 subjects on one unmodified and five geometrically modified cushions were determined using the Pressure Evaluation Pad. No significant differences were determined in the pressure measured for one modified cushion compared to the other modified cushions or for the control cushion. Independent effects of subject sex, diagnosis, and body build could not be identified so that no optimal modification was noted for any subpopulation of the total patient group. Marked individual variation and responsiveness were noted between cushions for any given patients. These data demonstrate that individualization of the prescription of a wheelchair cushion is essential for optimal pressure relief, and that no cushion appears to be universally superior for all patients or for any subgroup of patients requiring pressure relief devices.